Attack exploits just-patched Mac security bug

Fix my browser, fan pleads

If you haven't installed the latest security update for Mac OS X, now would be a good time.

A security researcher has released a proof-of-concept attack that exploits critical vulnerabilities that Apple patched on Thursday. The vulns stem from bugs in the Java runtime environment that allow attackers to remotely execute malicious code. Sun Microsystems patched the flaws early last month.

"I know that having a POC in hand bumps Apple's priority, so I sent them the POC and made them aware of the issue," said the researcher, Kevin Finisterre, a co-founder of security firm Netragard. "I honestly wanted my browser fixed."

Finisterre said he read through the patch details and researched where in OS X he thought the bug would be located. He sent the exploit to Apple employees on November 6, three days after Sun released a Java patch for Windows, Linux, and Solaris. Now that Apple has finally fixed the bug, he has gone ahead and made the code public.

The exploit is fairly rudimentary, but Finisterre said he plans to weaponize it soon. For the moment, browsers on unpatched systems that hit the exploit will crash. Behind the scenes, though, users will find their extended instruction pointers have been set to 0x41424344, a value that indicates a machine has been compromised.